Christophe Leroy <christophe.le...@csgroup.eu> writes: > Le 20/09/2021 à 15:55, Nathan Lynch a écrit : >> If, due to bugs elsewhere, we get into unregister_cpu_online() with a CPU >> that isn't marked hotpluggable, we can emit a warning and return an >> appropriate error instead of crashing. > > Is it only a bug situation, or is it something that can happen in real > life ? > > If it can happen in real life, kernels with panic_on_warn will still be > impacted.
I only found this by inspection, and it can happen only due to a bug in CPU device registration at boot. The flag must not be set if the platform or CPU can't support going offline.
